Weather conditions may impact driving conditions. For example, rain, snow, and sun glare may all slow vehicle speed. These weather conditions may also cause traffic congestion and other traffic incidents, such as vehicle accidents. Thus, it is beneficial for a driver to know not only the weather conditions, but how these conditions impact traffic.
Systems have been developed to provide drivers with alerts based on both traffic and weather data. These alerts may be provided for a road or area. For example, an alert may warn that traffic on a stretch of a highway is congested due to a thunderstorm in the area. These alerts may also be customized for an individual driver who has specified his planned route. For example, a driver may use a navigation system to specify a route and based on the specified route, the driver may receive an alert that the driver will experience slow driving conditions due to rain in the area of the specified route.
Some of these systems may use map data to display weather and/or traffic conditions on a map. The map data is stored in a geographic database and includes road location data that can be used to generate a map of a geographic area. As a result, a driver may receive visual information regarding the impact of weather and/or traffic conditions on the driver's planned route.
A geographic database may include more data than is used for generating a map. For example, the geographic database may include data representing curvature, grade, bank, lanes, bridges, tunnels, road warning signs, and so on. This data may be stored in the geographic database for reasons other than map display, such as for route calculation and route guidance. This data may also be used by Advanced Driver Assistance Systems (ADAS), such as adaptive headlight aiming, adaptive cruise control, lane departure warning and control, curve warning, speed limit notification, predictive cruise control, and adaptive shift control.
It would be beneficial to use this additional data in the geographic database to provide driving condition alerts.